Electric terminal



I R. B. VESSEY AND A. SCHMIDT.

ELECTRIC TERMINAL.

APPLICATION FILED JAN-17,1919.

PatentedSept. 27, 1921.

' UNITED STATES PATENT OFFICE.

RALPH- ."B: VESSEY AND ALBERT SCHMIDT, OF FLINT, MICHIGAN, ASSIGNORS TO cnmrron IGNITION MICHIGAN.

COMPANY, OF FLINT, MICHIGAN; A. CORPORATION OF ELECTRIC TERMINAL.

Specification of Letters Patent. Patented Sept. 27, 1921.

Applicationflled January 17, 1919. Serial No. 271,624.

reference being had therein to the accompanying drawings.

The invention relates to electric terminals designed for engagement. with connectors. and having particular reference to construe tions adapted for use on spark plugs.

It is the obj ect of the invention to obtain a simple construction which may be used with several. different types of connectors, as hereinafter set forth.

In the'drawings: Figure 1 is an elevation of the terminal as applied to a spark plug;

Fig. 2 is a vertical central section there through.

Fig. 3 is a similar view showing an eye terminal in engagement therewith. In the present state of the art it is usual 'to provide spark plugs with terminals formed by a threaded stud for extension of the insulated electrode and a clamping nut engaging said stud. Various types of connectors have beenused in connection with the plugs, the chief of-which are, first, an eye member for engaging the stud which is clamped by the nut; second, a spring socket contact for engaging a stud bearing on the nut; and third, a slotted contact ,member which is insertible in a narrow groove in the terminal. To provide for the latter con struction, it is usual to form the nuts narrow grooves therein having no! other function than for engaging this type of terminal; Where the nuts are formed of soft metal, such grooves may be readily machined therein, but for other types of nuts, and particularly where formed of pressed sheet-metal, it is difiicult to provide such agroove. The present invention overcomes the difficulty by forming a' narrow groove. between a portion of the threaded stud and the lower face of the nut, this being'accomplished by a shoulder on the stud, v

slightly spaced from the bearing for the connector. Thus the nut when screwed down upon the stud will be held spaced from This will leave a narrow the bearing, but at the same time an eye type of connector, which is always of greater thickness than the slot, will be clamped against the bearing on the stud by the nut.

In detail, A is the terminal or electrode extending outward from the insulator B of a spark plug. C is a collar portion of enlarged diameter on the terminal A which forms on its outer face a bearing D for the connector. Extending outward beyond this collar C is the threaded stud E with which a' clamping nut, such as F, may be engaged.

To form the groove for engaging the slot-. ted terminal the stud E is shouldered at G a slight distance above the hearing I) so that the nut when screwed inward Wlll be limited in its movement by said shoulder G. oove H between the nut and the bearing which will receive the slotted terminal. To form the shoulder G, the portion of the stud I below the same is of slightly greater diameter, but the dimension is limited so that it will receive an eye connector such as J, permitting the -latter to rest upon the bearing D; the connector J being of greater thickness. than .the distance between the shoulder G and larger diameter. Withinthe latter portion.

is a disk member M which is centrally apertured and threaded for engaging with the stud E. This type of nut is not essential to the present invention, but inasmuch as --it would be di'flicult to form the narrow groove inthe pressed sheet metal, the shouldered stud is particularly advantageous when used. in connection therewith.

Although I have shown and described the nut orcap member the same is covered by my copending application entitled Electric termlnal fitting, Serial No. 271,623, filed J anuar 17, 1919.

at weclaim as our. invention is:

1. An ."electric terminal, comprising a threaded stud member, a' laterally-extending bearing portion on said stud member for engagement with a connector, a clamping nut engaging-the threaded stud, and means for shoulder forming a stop for said nut holding the same spaced from said bearing to form a narrow groove therebetween.

3. An electric terminal, comprising a threaded stud, a laterally-extending collar on said stud for receiving a connector, a nut engaging the threaded stud, and a portion of said stud of slightly greater diameter than the threaded portion forming a shoulder limiting the inward movement of the nut to form a narrow groove between the same and said bearing.

4. An electric terminal, comprising an insulated threaded stud, an annular collar on said stud forming a seat for a connector, a nut engaging the threaded stud for exerting a clamping pressure upon an eye connector when seated on said bearing, and a shoulder on said stud spaced from said bearing by less than the thickness of said eye connector for limiting the inward movement of said nut to form a narrow groove.

In testimony whereof we affix our signatures.

RALPH B. VESSEY. ALBERT SCHMIDT. 

